We consider buying an apartment, which has previously been used as a shop. Our only concern is that it has large windows (2,5 meters x 2,5 meters), which would function like an invitation to burglars. I am thinking that we could buy bullet-proof glass to make it much more difficult for burglars, though, I have never heard about anyone doing this, and I have not been able to find any shops selling such glass. Therefore, I was wondering whether bullet-proof glass of this size would really help against burglars, and what we would be talking about with regards to price compared to ordinary glass (are we talking about hundreds of thousands of dollars per window or just a few thousands)?

EDIT: I am not so worried about economic loss, this is more an issue of whether I would actually get out of bed if I heard strange noises in the apartment at night.

Lexan (Polycarbonate) at 1" thick will stop most handgun bullets, but rifle rounds may not be stopped.
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Tester101♦Sep 21 '11 at 15:24

@Tester101 I am not so worried about anyone shooting at the glass, I am more concerned that they will be able to break it somehow and get in. If they shoot, they will alarm a lot of people.
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DavidSep 21 '11 at 16:56

I'd be more paranoid about people looking in, and needing to have the curtains drawn at all times ... or drunk people thinking it looks like a shop at night, and trying to come in. (I've heard about this happening w/ converted buildings)
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JoeSep 22 '11 at 4:55

9 Answers
9

There is a product called Window Security Film which is a thin (a couple mm) film that adheres to the window and makes it exceptionally difficult for someone to break. Many lock smiths/security companies can install it. Here's a video of it in action: http://www.youtube.com/watch?v=vYdVK3BqPfk

One of the biggest "problems" with it however is that because it's invisible, people will still try to break the glass. For this reason, often it is installed along with window bars since this provides a visual deterent, but they are pretty ugly for residential installs.

I was worried about the price of this, but is seems to be very low compared to bullet proof glass. Thanks for the tip!
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DavidNov 29 '11 at 22:16

they used it all the time on 'It Takes a Thief'
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warrenNov 26 '12 at 19:08

Window film is a good answer. Lexan glazing (NOT a ballistic version, just shatter-resistant plastic!) is another good answer, and may look nicer, but is more expensive and may be somewhat more scratch-prone.
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keshlamOct 30 '14 at 22:49

Another angle - if it is the size of windows you are worried about, have you thought about altering the frontage to have smaller windows? It would then look less like a shop, and it would be easier to get toughened/laminated glass for the windows.

Put in a simple alarm system with glass break sensors. Dedicate it to the windows if necessary and leave it on all the time. If anyone ever tries to break a window the alarm will sound. You would not even need to have it monitored if all you want is peace of mind while sleeping.

That does not stop someone breaking the glass, it is a real pain to get windows fixed even if the person runs away after the alarm goes off. If you don't get the windows fixed without hours, they can just keep setting the alarm off until it get's ignored, then go in!
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WalkerNov 30 '11 at 12:56

This doesn't answer the question at all. Why so many up votes!?
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iconoclastOct 23 '12 at 0:22

In his edit David says he wants to sleep well at night. An alarm would do this for him. That is why I gave the answer, and I guess that is why it is being up voted.
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Scott BrunsOct 23 '12 at 1:01

I'm pretty sure bullet proof glass is not a viable option. A quick Google search came up with a 40" wide window for over $3k. I couldn't find anything nearly the size you mentioned, and I'm guessing the cost for increasing scale is not linear - you're talking at least tens of thousands of dollars here. My guess is that the glass would end up costing just about as much as the apartment, if not more. Plus, bullet proof glass isn't completely shatter-proof. An attempt to break it could leave it cracked, and there goes the most expensive thing in your apartment.

Plus you've got to consider if the window is even your most vulnerable point of entry. Do the doors have steel frames? Are the deadbolts bump proof? If you're that worried about break-ins, my advice would be a good renter's insurance policy and a burglar alarm system.

An alternative to bullet-proof could be shatter-resistant. Lexan can be purchased in 4'x8' sheets for $167 at most home improvement stores. You'd probably have to have panels that large (2.5m x 2.5m) custom made though. Be warned that Lexan is not scratch-resistant though, so you may have unbroken but scratched up windows.

If it's a high crime area, the typical solution is window bars on the first floor.

If it's not a high crime area, I'd maybe not panic too much. Most burglaries are through the front or back door or an open window. Smashing large picture windows isn't typically the first choice of a burglar.

The type of glass by itself isn't a deterrent as most burglars don't look first, or they don't know what they are looking at. Signage is a greater deterrent.

The window film as already suggested is most likely the simplest and cheapest solution.

Bullet resistant glass will deter burglars once they throw a brick or take a few swings at the glass and realize that it is still there. This can still break the glass, which will be a very costly replacement. Laminated glass will do a much better job as it will have the same effect. Laminated glass is two pieces of glass bonded together with a plastic. This is how bullet resistant glass is made as well, but with many more layers, thicker glass, and thicker plastic.

The idea of a security film is very similar to why laminated glass is a suitable security glass.

How about getting some electric hurricane shutters? Or get some nice ironwork to function as burglar bars. If you wanted something cheap and fast, get some 2 by 4's, cut them up in a design, screw them together with wood screws, putty them up, route the edges, sand them, a little paint and you have an instant burglar bar.

Paint metal bars to match your siding or paint them white. Put them on the interior so it looks more like a window grid. Once a burglar sees it they most likely won't even try breaking the windows. Put security stickers on the windows, and on top of that use shock sensors.

You really don't have to splurge on bullet proof glass; just use regular glass with the bullet resistant film. If you live in a high crime area consider moving.

Most thieves don't want the attention of shooting off a gun but some will. So even if they do use a gun they will set the alarm off and have the bars to get through.